The italicized font represents information to be shared orally or physically completed with the students at this time.

The non-italicized font represents additional information included supporting the teacher’s understanding of the content being introduced within the CELL.

ASK WHY

Remind students that heat, thermal energy, and temperature greatly influence the way we live. We monitor our body temperature, dress for the hot and cold, build homes, schools, and cars with heating and cooling systems, and passionately search for alternative fuels as the threat of global warming takes hold. To live safely and productively, it is important to understand the thermal behaviors that govern our bodies and the world. 

BRANCH OUT

Remind students that climatologists monitor data from several Earth-observing satellites that act as thermometers in space. Using satellite data, they can create a record of land surface temperatures all over the world.

GET FOCUSED

Inform students that the Investigation is designed to help them to answer the following Focus Question:

• How can the ability to absorb heat be measured as a specific physical property of matter? This Investigation involves calculating a property of matter called specific heat capacity. Specific heat capacity is a measure of the amount of heat energy (joules) required to raise the temperature of 1 gram of a substance by 1 degree Celsius.

Note: This question is located in students’ SDRs at the beginning and end of the Investigation.

Note: This is a succinct response to the Focus Question and is placed here for your reference at this time. A fully developed response to the Focus Question can be found on the PostLab page.

GO DEEPER

As a class, read the Background(s) in the Investigation. Have students read the information aloud or silently to themselves. When students have finished, discuss the following concepts as a class:

• Different substances have different capacities for absorbing and retaining heat energy.
• The specific heat capacity of a substance is a value that describes the amount of heat energy (Joules) required to increase the temperature of 1 g of the substance by 1^oC.
• A substance that has a low specific heat capacity becomes hotter much faster than one with a high specific heat capacity.
• Specific heat capacity is measured in units of Joules per gram per ^oC.

Note: These concepts are integrated into the Background(s) and are used to deepen students’ comprehension of the big ideas.

LEARN THE LabLearner LINGO

The following list includes Key Terms that are introduced in the Investigation Background(s). They should be used, as appropriate, by teachers and students during everyday classroom discourse.

• specific heat capacity
• Joules

Note: Definitions to these terms can be found on the Introduction page to the CELL.

Note: Additional words may be bolded within the Background(s). These words are not Key Terms and are strictly emphasized for exposure at this time.

SET FOR SUCCESS

• Inform the students that the amount of heat lost by one substance is equal to the amount of heat gained by another substance and that this obeys the Law of Conservation of Energy.
• Assess the background knowledge of the students by asking them to complete the prediction questions in their SDRs.

Note: Students will be able to formulate answers to these questions after they have completed the Investigation.

• Discuss the Law of Conservation of Energy and how heat loss and gain obeys its definition.
• Inform students that in this Investigation they will determine the amount of heat lost by an object and heat gained by a certain volume of water.
• Discuss the calculation to determine the amount of heat gained by the water.

Mass of the cold water (g) x change in temperature (^oC) x 4.184 J/g ^oC

• Explain that the heat lost by a solid was equal to the heat gained by the water.

Heat lost by hot solid = Heat gained by cold water

• Discuss the concept of specific heat capacity and use the example of cooking utensils with wooden handles vs. cooking pots being made of metals.
  • Wood has a high specific heat capacity therefore a great amount of heat is needed to increase its temperature, therefore making it safer for us to use, as compared to metal cooking pots which have a low specific heat capacity requiring very little heat energy to increase the temperature.
  • Generally speaking, non-metals like wood have a higher specific heat capacity compared to metals.
• Discuss the calculation for determining specific heat capacity.

• Explain to students that they will determine the specific heat capacities for two different metals. They will determine which one would heat faster based on this result.
• Outline to students that specific heat capacity and the amount of heat a substance contains is an inverse relationship; the lower the specific heat capacity the hotter a substance gets when heated.
• Play the video below. Stop to ask students questions or answer students’ questions when necessary. Remind students to follow along with their SDRs and make any notes that they think might be helpful.
• After the video, direct students to divide into their lab groups to discuss their strategy for the lab. For example, they may assign certain group members to perform specific functions during the lab.

Note: The purpose of the video is to allow students to anticipate the laboratory experience they will soon encounter. Students should leave this PreLab session with a firm idea of what to expect and how to perform in the lab.

Note: Homework is posted below the video.

HOMEWORK

Tell students that they should review the Investigation in preparation for the Lab.